1. Field of the Invention
This invention relates in general to communication systems and in particular to systems for communication of location sensitive information in public and private systems.
2. Description of the Related Art
Satellite navigational systems provide a means of locating and tracking communications devices. These systems include Navstar, GPS, and other systems that comprise a plurality of space vehicles (SV) or satellites making up constellations. The Global Positioning System (GPS) is a worldwide radio-navigation system formed from a constellation of twenty-four satellites and their ground stations. GPS uses these xe2x80x9cman-made starsxe2x80x9d as reference points to calculate positions accurate to a matter of meters. The GPS receiver uses the satellites in space as reference points for locations here on earth. The GPS receiver measures distance using the travel time of radio signals. The GPS receiver has very accurate timing to measure travel time. Along with distance, the GPS receiver knows where the satellites are in space. Finally, the GPS receiver corrects for any delays the signal experiences as it travels through the atmosphere.
Public safety agencies need to track the location of their personnel within and outside of their vehicles. Currently, in the mobile radio environment, location data is acquired from the position of the mobile radio. However, as public safety personnel move away from their vehicles, the location information becomes less accurate as the information remains associated with the vehicle as opposed to the individual. It would be preferable to have the GPS location information more closely associated with the individual. Improvements in location search time and accuracy are also beneficial.
Disadvantageous to having GPS information transferred from a portable device is the added cost and size requirements associated with the inclusion of onboard location determining components. However, with the increase in the number of devices worn by public safety personnel, it would be beneficial to incorporate as much functionality into existing devices as possible.
What is needed is a communication system and method for facilitating the identification of location sensitive information for a portable device with improved precision location and improved search time.